Katrina, Rita caused forestry disaster

Satellite views surprising to researchers

November 16, 2007|By Marc Kaufman The Washington Post

WASHINGTON — New satellite imaging has revealed that hurricanes Katrina and Rita produced the largest single forestry disaster on record in America - an essentially unreported environmental catastrophe that killed or severely damaged about 320 million trees in Mississippi and Louisiana.

The die-off, caused initially by wind and later by pooling of stagnant water, was so massive that researchers say it will add significantly to the greenhouse gas buildup - ultimately putting as much carbon from dying vegetation into the air as the rest of the American forest takes out in a year of photosynthesis.

In addition, the downing of so many trees has opened vast and sometimes fragile tracts of land to several aggressive and fast-growing exotic species that already are squeezing out far more environmentally productive native species.

Efforts to limit the damage have been handicapped by the ineffectiveness of a $504 million federal program to Gulf Coast land owners to replant and fight the invasive species. Congress appropriated the money in 2005 and added to it in 2007, but officials involved with the emergency conservation program say that only about $70 million has been processed or dispensed so far. Local advocates say onerous bureaucratic hurdles and low compensation rates are major reasons why.

"This is the worst environmental disaster in the United States since the Exxon Valdez accident ... and the greatest forest destruction in modern times," said James Cummins, executive director of the nonprofit environmental group Wildlife Mississippi and a board member of the Mississippi Forestry Commission. "It needs a really broad and aggressive response, and so far that just hasn't happened."

Bengt "Skip" Hyberg, a U.S. Department of Agriculture Farm Service Agency economist and policy analyst, said changes were made in the program this year to make it more attractive to landowners

The U.S. Forest Service and Farm Service Agency had estimated the forest damage from two 2005 hurricanes, but they focused on economic losses - $2 billion, or 5.5 billion board feet, worth of timber.

The new assessment of trees killed or severely damaged comes from a study to be released today in the journal Science, written primarily by researchers at Tulane University in New Orleans who studied images from NASA satellites.

Lead author Jeffrey Chambers said the team used a before-and-after method perfected by researchers who study the Amazon basin to assess the damage caused by logging. The satellite images identified green vegetation before the storm and wood, dead vegetation and surface litter after the storm. The team then visited areas of greatest damage to make an overall assessment.

"I was amazed at the quantitative impact of the storm," Chambers said. Of the 320 million trees harmed, he said, about two-thirds soon died.

Chambers was even more surprised when his team calculated the amount of carbon that will be released into the atmosphere as the trees and other storm-damaged vegetation decomposes. The total came out to be about 1.1 billion tons, equal to the carbon that all the trees in the United States capture and take out of the atmosphere in a year.

Much of the forest damage occurred in Mississippi on land often owned in small parcels by individuals. Larry Payne, director for cooperative forestry for the Forest Service, said the congressional effort to restore the forest was largely aimed at helping out those small landowners, who often use their timber as a bank account. The program was created as an emergency add-on to the popular federal Conservation Reserve Program, which pays landowners "rent" for returning marginal or environmentally sensitive land to more natural conditions.

"Congress wanted to get money back into the hands of these people, and that was the top priority," he said. But Payne and Hyberg said the Gulf Coast landowners were subject to most of the same restrictions and compensation rates as Conservation Reserve participants around the nation, and that worked against efforts to jump-start reforestation in areas damaged by Katrina and Rita.

Officials said that a Mississippi tax credit program for forest land owners has apparently been more effective.

Hurricane Katrina came ashore along the Pearl River, which divides Mississippi and Louisiana and is ecologically very rich and diverse. The Chambers study found that native species like longleaf pine, live oak, and cypress did much better in surviving the hurricane than other species planted primarily for logging, such as loblolly and slash pine.

The native deciduous forests were severely damaged in some areas, and the young, slow-growing oaks and maples are already being squeezed out by Chinese tallow trees, imported for landscaping more than a century ago. It thrives in disturbed land, and foresters and environmentalists say it is running wild in the Katrina-damaged area. The tree produces a milky, toxic sap that keeps insects away, which in turn makes an inhospitable environment for birds and small mammals.